Antacids have been used for generations to treat excess stomach acidity. Unfortunately, while many basic salts, such as sodium bicarbonate, offer prompt relief of acid indigestion, many of these basic compounds have the disadvantage of causing "acid rebound." In other words, because these salts have such a high pH, they overcompensate for the excess stomach acid and raise the pH of the stomach to too high a level. To overcome this increased pH, then, the stomach secretes even more acid--the acid rebound effect. This acid rebound, of course, negates the effect of the antacid, and the vicious cycle resumes.
In an effort to avoid acid rebound, many have switched to antacids based upon aluminum salts such as aluminum hydroxide. However, aluminum has now been associated with a variety of other problems, such as Alzheimer's disease and possible renal failure, so that it is now desirable to avoid ingesting antacids containing aluminum salts.
Additionally, conventional antacids are often fast acting but have no lasting effect. In other words, these compositions provided quick relief which was not sustained over a period of several hours, resulting in the need to ingest additional quantities of antacid salts.
Guar gum has been used as an antacid, as disclosed in U.S. Pat. No. 4,764,374, which corresponds to French A-2 578 423, the entire contents of which are hereby incorporated by reference.